Eupatorium perfoliatum L.

Alternate Common Names: boneset, thoroughwort

Scientific Synonyms: Eupatorium chapmanii Small, Eupatorium perfoliatum var. colpophilum Fernald & Griscom, Eupatorium perfoliatum var. cuneatum Engelmann

Family: ‌aster or sunflower family (Asteraceae)

Functional Group: forbs (wildflowers)

Description 

Life cycle and growth form

Perennial, short-rhizomatous, spreads slowly to form small colonies.

Height: 2-4 ft

 

Leaves and stem

Leaves join around the stem making them look like one leaf (perfoliate) and then taper to a point, opposite arrangement (rarely whorled), leaf margins are wavy with small teeth (crenulate), leaf surfaces have a wrinkled appearance, upper and lower leaf sides are hairy; stems are hairy, erect, and branched in the upper portion of the plant.

 

Flower, fruit and seedhead

Flower: Tiny heads (1/4 in) of up to 15 disc florets (no visible “petals” or rays), grouped in flat-topped to slightly domed clusters of dozens to hundreds of heads; flower clusters appear fuzzy due to thin styles that extend from each floret.

Fruit/seedhead: Clusters become fluffy from the center outwards as seeds mature and pappus expands.

Pollination: Insects, particularly bees, butterflies, flies, beetles, and wasps.  

 

Seed

Appendix D

‌Seed characteristics 

Seeds per ounce: 160,000 (IA NRCS)

1000 seed weight: 0.11 g (Seed Information Database)

Description: Long slender, dark gray seeds (achenes) up to 2.5 mm long with a short tuft of white hairs (pappus).

Typical seed test 

PLS: 68% (n = 6)

Purity: 71% (n = 6)

Germination: 16% (n = 5)

Dormant: 81% (n = 5)

(averages obtained from n tests of purchased seed lots)

Habitat and range

‌Habitat: Moist to wet, organic-rich soil; full sun; wet pastures, sedge meadows, fens; The USDA classifies it as an Obligate Wetland species in the Midwest region. It benefits from irrigation in production systems.

Conservation status: Global- G5, secure; Kansas- S3, vulnerable (NatureServe)

‌

General Comments

The clouds of sweet-scented flowers attract a diverse assemblage of pollinating insects. Bitter compounds in the foliage deter mammalian herbivores, although some moth larvae use common boneset as a host plant. This species has traditional medicinal and ceremonial uses among Native tribes within its range, and was adopted as a treatment for colds and fevers by colonial settlers. It is currently under investigation by researchers in Germany and India for use in treatment of viral illnesses such as colds, flu, and dengue fever as well as malaria. Caution: this plant also contains phytochemicals that may be toxic to the liver.

Recommendations for Seed Production 

Establishment for seed production

‌Direct seeding

We do not have experience direct seeding this species for seed production. It reportedly has low germination rates in direct seedings. High seeding rates and fall planting are recommended.

‌‌Greenhouse

Seed pre-treatment: 60 days cold-moist stratification.

Sowing: Seed is small and should be surface sown. If started in germination flats, transplant to individual plugs when seedlings have their first pair of true leaves, about 4 weeks after seeding.

Transplanting: Seedlings are ready to transplant to the field about 6-8 weeks after being transferred to plugs, when their roots are well-branched and numerous root tips are visible at hole(s) in the base of the plug. Pop out a few plugs to check for adequate root development that will provide sturdy plugs for planting. Seedlings are fast growing and may need to be clipped back before transplanting to improve the shoot:root ratio. A week or two before transplanting, move flats outside to ‘harden off.’ (See Propagation chapter in General Information for more details).

‌Appendix A

Stand management

Weeds: In the first season after transplanting, weeds are suppressed by a plastic weed barrier. Plants spread slowly by short rhizomes; in second and subsequent years, holes in plastic may need to be expanded or plastic removed to make room for new stems. Well-established plots shade out most weeds.

Pests: None noted.

Diseases: None noted.

Soil moisture: Irrigation is necessary in most soils to obtain maximum seed yield.

Seed production

First harvest: Plants flower and set a little seed the first year when transplanted in spring.

Yield: 80-130 pounds/acre (based on 1 plot)

Stand life: unknown

Flowering date: August - September in northeast Iowa

 

Seed maturity/Harvest date: mid-September - mid-October

Seed retention: Seeds are wind dispersed soon after maturity, when fluff (pappus) expands in late September through mid-October.

Harvest date range at TPC (2022-2023): Sept 15 - Oct 7

Recommended harvest method: Watch for the centers of seed clusters to begin shattering, and pick early maturing seed heads (clip stalks below seed clusters). If some heads in a cluster are still closed (not fluffy), pull apart a few heads to see if the seeds are dark colored and separate easily from the base (receptacle). Combine the rest of the plot at peak maturity. Turn off air or combine will disperse the fluffy seeds.

Appendix B

Seed cleaning and storage

Cleaning process: If hand clipped, run dried material through a 1/4 in mesh to thresh seed from stalks. Use a brush machine (soft bristles, minimum vacuum) to remove pappus. Seed is fragile, and some seed is dehulled, even when soft bristles are used. Winnow with a box fan to separate seed from most of the pappus and chaff. Airscreen 2-3 times to finish cleaning. See Appendix C for specific settings.

Seed storage: cool/dry (33-50° F, 30-50% RH) for up to 3 years (USDA Plant Fact Sheet).

Appendix C

Released Germplasm 

Source Identified material: Natural Selections/Iowa Ecotype Zone NI

References

Belt, S. (2009). Plant fact sheet for common boneset (Eupatorium perfoliatum L.). USDA-Natural Resources Conservation Service, Norman A. Berg National Plant Materials Center, Beltsville, MD  20705.

Chayka, K. (n.d.). Eupatorium perfoliatum (common boneset). Minnesota Wildflowers. https://www.minnesotawildflowers.info/flower/common-boneset

Cochrane, T. S., Elliot, K., & Lipke, C. S. (2014). Boneset. In Prairie plants of the University of Wisconsin-Madison Arboretum (3rd ed., p. 79). University of Wisconsin-Madison Arboretum.

Eupatorium perfoliatum. (n.d.). Prairie Moon Nursery. https://www.prairiemoon.com/eupatorium-perfoliatum-boneset-prairie-moon-nursery.html 

Hilty, J. (2019). Common boneset - Eupatorium perfoliatum. Illinois Wildflowers. https://www.illinoiswildflowers.info/prairie/plantx/cm_boneset.htm

Kartesz, J.T., The Biota of North America Program (BONAP). 2023. North American Plant Atlas. (http://bonap.net/napa). Chapel Hill, N.C. [maps generated from Kartesz, J.T. 2023. Floristic Synthesis of North America, Version 1.0. Biota of North America Program (BONAP). (in press)]

NatureServe. 2024. NatureServe Network Biodiversity Location Data accessed through NatureServe Explorer [web application]. NatureServe, Arlington, Virginia. Available https://explorer.natureserve.org/. (Accessed: February 28, 2024).

SER, INSR, RBGK, Seed Information Database (SID). (2023). Eupatorium perfoliatum. https://ser-sid.org/species/e29e87df-3177-43f1-bfcd-bc052339de84

USDA NRCS National Plant Data Team. (n.d.). Eupatorium perfoliatum L. USDA plants database. https://plants.usda.gov/plant-profile/EUPE3

Siripun, K. C., & Schilling, E. E. (2020, November 6). Eupatorium perfoliatum Linnaeus. Flora of North America. http://floranorthamerica.org/Eupatorium_perfoliatum 

Species Guide Updated 12/18/2024

Doellingeria umbellata (Mill.) Nees 

Alternate Common Names: flat-top aster, parasol aster, tall flat-topped white aster

Scientific Synonyms: Aster umbellatus Miller, Diplopappus umbellatus (Miller) Hooker, Diplostephium umbellatum (Miller) Cassini

Family: ‌aster or sunflower family (Asteraceae)

Functional Group: forbs (wildflowers)

Description 

Life cycle and growth form

Long-lived perennial, spreads by short rhizomes to form small colonies.

Height: 1-5 ft

 

Leaves and stem

Lance-shaped, 3-5 in long and 1/2-1 in wide, leaf margins toothless, leaf surfaces usually hairless or with short hairs, alternate arrangement; stems are erect and unbranched except within the flower head, with few to no hairs, generally light yellowish-green but sometimes purple.

 

Flower, fruit and seedhead

Flower: Individual heads are daisy-like, about 1/2 in wide, with yellow to tan centers and usually 5-10 (up to 15) white “petals” (rays) irregularly arranged around the central disc; dozens to hundreds of heads in a branched, flattened cluster up to 10 or 12 in wide.

Fruit/seedhead: Seed head appears fuzzy due to creamy-white fluff (pappus) on seeds.

Pollination: Insects, including bees, butterflies, and moths

 

Seed

Appendix D

‌Seed characteristics 

Seeds per ounce: 67,000  (IA NRCS)

1000 seed weight: 0.7 g (Seed Information Database)

Description: Seed (achene) is light brown, 2.5-3 mm long, approximately 1 mm wide near the top, tapered to a point on the lower end, and bears a “parachute” of creamy white fluff (pappus).

Typical seed test 

PLS: 85% (n = 5)

Purity: 90% (n = 5)

Germination: 22% (n = 4)

Dormant: 71% (n = 4)

(averages obtained from n tests of purchased seed lots)

Habitat and range

‌Habitat: Moist to wet soils, preferably with some sand; partial to full sun; wet prairies, sedge meadows, seasonally wet ditches, and fens; benefits from irrigation in production systems. The USDA classifies it as a Facultative Wetland species in the Midwest region.

Conservation status: Global- G5, secure; Delaware, Iowa, and North Carolina- S3, vulnerable (NatureServe) 

‌

General Comments

Parasol whitetop is a late season nectar and pollen source for diverse species of bees (including specialist bees), wasps, beetles, flower flies, and skipper butterflies. It is a larval host to some species of checkerspot and crescent butterflies. It can grow and flower for many years in mesic soils but benefits from irrigation in production systems.

Recommendations for Seed Production 

Establishment for seed production

‌Direct seeding

We do not have experience with direct seeding this species for seed production.

‌‌Greenhouse

Seed pre-treatment: 60 days cold-moist stratification results in uniform and high rates of germination.

Sowing: Seed is small and should be only lightly covered with growing media. If started in germination flats, transplant to individual plugs when seedlings have their first pair of true leaves, about 2 weeks after seeding.

Transplanting: Seedlings are ready to transplant to the field about 6-8 weeks after transferring them to plugs, when their roots are well-branched and numerous root tips are visible at hole(s) in the base of the plug. Pop out a few plugs to check for adequate root development that will provide sturdy plugs for planting. Seedlings are fast growing and may need to be clipped back before transplanting to improve the shoot:root ratio. A week or two before transplanting, move flats outside to ‘harden off.’ (See Propagation chapter in General Information for more details).

‌Appendix A

Stand management

Weeds: In the first season after transplanting, weeds are suppressed by a plastic weed barrier. Plants spread slowly by short rhizomes; in second and subsequent years, holes in plastic may need to be expanded or plastic removed to make room for new stems.

Pests: None noted.

Diseases: None noted.

Soil moisture: This species benefits from drip irrigation when planted in mesic soils.

Seed production

First harvest: Plants will flower and produce a small amount of seed in the planting year when started from transplants.

Yield: 28-74 pounds/acre (based on 1 plot)

Stand life: unknown

Flowering date: August - September

Seed maturity/Harvest date: late September - late October

 

Seed retention:  Seeds are wind dispersed soon after maturity, when fluff (pappus) expands in late September through October.

Harvest date range at TPC (2022-2023): Sept 15 - Oct 20

Recommended harvest method: Seed is released from heads within days of the fluffy “parachutes” expanding. Watch for the centers of seed clusters to begin shattering, and pick early maturing seed heads (clip stalks below seed clusters). If some heads in a cluster are still closed (not fluffy), pull apart a few heads to see if the seeds are dark colored and separate easily from the base (receptacle). Combine the rest of the plot at peak maturity. Turn off air or combine will disperse the fluffy seeds.

Appendix B

Seed cleaning and storage

Cleaning process: If hand clipped, run dried material through a 1/4 in mesh to thresh seed from stalks. Use a brush machine (medium bristles, low vacuum) to remove pappus. May need two rounds of brushing. Winnow with a box fan to separate seed from most of the pappus and chaff. Airscreen 2-3 times, then indent to remove broken bits of stems. See Appendix C for specific settings.

Seed storage: cool/dry (33-50° F, 30-50% RH)

Appendix C

Released Germplasm 

Source Identified material: Natural Selections/Iowa Ecotype Zone NI

References

Chayka, K. (n.d.). Doellingeria umbellata (flat-topped white aster). Minnesota Wildflowers. https://www.minnesotawildflowers.info/flower/flat-topped-white-aster 

Cochrane, T. S., Elliot, K., & Lipke, C. S. (2014). Flat-top aster. In Prairie plants of the University of Wisconsin-Madison Arboretum (3rd ed., p. 133). University of Wisconsin-Madison Arboretum.

Hilty, J. (2019). Flat-topped aster - Doellingeria umbellata. Illinois Wildflowers. https://www.illinoiswildflowers.info/wetland/plants/fltp_aster.html

Kartesz, J.T., The Biota of North America Program (BONAP). 2023. North American Plant Atlas. (http://bonap.net/napa). Chapel Hill, N.C. [maps generated from Kartesz, J.T. 2023. Floristic Synthesis of North America, Version 1.0. Biota of North America Program (BONAP). (in press)]

NatureServe. 2024. NatureServe Network Biodiversity Location Data accessed through NatureServe Explorer [web application]. NatureServe, Arlington, Virginia. Available https://explorer.natureserve.org/. (Accessed: February 28, 2024).

Society for Ecological Restoration, International Network for Seed Based Restoration and Royal Botanic Gardens Kew. (2023) Seed Information Database (SID). Available from: https://ser-sid.org/ (February 2023)

USDA NRCS National Plant Data Team. (n.d.). Doellingeria umbellata (Mill.) Nees. USDA plants database. https://plants.usda.gov/plant-profile/DOUM2

Van Der Grinten, Martin. (2001). Propagation protocol for production of Container (plug) Aster umbellatus P. Mill. plants USDA NRCS - Big Flats Plant Materials Center Corning, New York. In: Native Plant Network. URL: https://NativePlantNetwork.org (accessed 2024/02/02). US Department of Agriculture, Forest Service, National Center for Reforestation, Nurseries, and Genetic Resources.

Semple, J. C., & Chmielewski, J. G. (2020, November 6). Doellingeria umbellata (Miller) Nees. Flora of North America. http://floranorthamerica.org/Doellingeria_umbellata

Species Guide Updated 12/20/2024

Heliopsis helianthoides (L.) Sweet

Alternate Common Names: common ox-eye, false sunflower, sunflower heliopsis, ox-eye, sunflower-everlasting

Scientific Synonym: Buphthalmum helianthoides L.

Family: ‌aster family (Asteraceae)

Functional Group: forbs (wildflowers)

Description 

Life cycle and growth form

Perennial, fibrous rooted, producing clumps or colonies from rhizomes.

Height: 2-6 ft

Leaves and stem

Leaves opposite, egg-shaped with pointed tips, saw-tooth margins, rough texture, up to 5 in long and 3.5 in wide; stem is erect, rough with short hairs, branched.

Flower, fruit and seedhead

Flower: One to 15 sunflower-like yellow flower heads, 1.5-3 in (4-7.5 cm) in diameter, at ends of long stalks from stem tip and upper leaf axils; ray florets are yellow-orange color, center disk usually golden yellow; underside of the flower head with alternating short and long bracts (phyllaries).

Fruit/seedhead: Flower head matures to a head of “seed” (achenes); achenes are dark, 3-4 angled, 4-5 mm long, and lack pappus; both disk and ray florets are fertile and produce achenes.

Pollination: Insects such as bees, wasps, beetles, flies, and butterflies.

Seed

Appendix D

‌Seed characteristics 

Seeds per ounce: 6,300 (IA NRCS)

Seeds per pound: 100,800 (IA NRCS)

1000 seed weight: 4.15 g (Seed Information Database)

Description: Seed unit is a smooth, dark achene about 3/16 in (4-5 mm) long.

Typical seed test 

PLS: 95% (n = 10) 

Purity: 100% (n = 10)

Germination: 65% (n = 9)

Dormant: 31% (n = 9)

(averages obtained from n tests of purchased seed lots)

Habitat and range

‌Habitat: Dry-mesic to wet-mesic soil; full sun; low to high quality remnant prairies, disturbed areas, roadsides, railroads, woodland openings and edges, thickets, streambanks, limestone glades. Wetland Indicator Status is Facultative Upland (FACU) for the Midwest.

Conservation status: Global- G5, secure; Delaware- S1, critically imperiled; Louisiana- S3, vulnerable (NatureServe)

‌

General Comments

Smooth oxeye is a component of most tallgrass prairies with medium to dry soils where it grows in association with tall, warm-season grasses. The long flowering time and abundant nectar and pollen make this an important pollinator resource, and the nutritious seeds are eaten by birds and mammals. This species is fairly easy to establish by direct seeding, if good seedbed preparation and weed suppression are achieved. Extended flowering and seed-ripening period makes determining optimal combine harvesting time difficult. Seed cleaning is accomplished with air-screen cleaning.

Recommendations for Seed Production 

Establishment for seed production

‌Direct seeding

Row spacing: 30-36 in rows

PLS pounds/acre:  4.0

Seeds per linear foot: 40

Seeding depth: 1/4 in

Seeding method: native seed drill

Seeding time: dormant season

Weed control: Prepare clean, firm, weed free seedbed prior to seeding.

‌‌Greenhouse

Seed pre-treatment: Wet stratify 8-12 weeks at 40° F.

Sowing: Sow seed at 1/4 in depth about two months before the last frost-free date.

Transplanting: Harden off, transplant into bare soil in rows or weed barrier at 8 in intervals after all danger of frost. Since this species spreads by rhizomes to form clumps, remove weed barrier after establishment year or use biodegradable barrier.

‌Appendix A

Stand management

Weeds: Mow/cultivate between rows. Post emergence grass herbicide, tillage, roguing.

Pests: Plants may be affected by red aphids (Uroleucon) though these infestations are often cleared by parasitic wasps and aphid predators, and it is not clear that they cause much harm to the plants.

Diseases: Powdery mildew.

Seed production

First harvest: Some flowering and seed production in first growing season from transplants and in well-managed direct seeded stands.

Yield: 20-115 pounds/acre (per acre yield extrapolated based on production from 1 plot)

Stand life: Peak harvest second-fourth year with declining yields in subsequent years.

Flowering date: early June - late July in northern Iowa

Seed maturity/Harvest date: mid-August to late September in northern Iowa; complicated by long flowering and seed ripening period.

Seed retention: Shattering occurs mid to late October.

Harvest date range at TPC (2005-2008): Sept 15 - 21

Recommended harvest method: Combine

Appendix B

Seed cleaning and storage

Cleaning process: Pre-clean by scalping through 1/2 in and 1/4 in mesh to remove large plant matter and make flowable, then air-screen. (No awns or appendages to remove.)

Seed storage: cool/dry (33-50° F, 30-50% RH)

Appendix C

Released Germplasm 

Source Identified material: Central Iowa Germplasm (IA Zone 2), Northern Iowa Germplasm (IA Zone 1), Southern Iowa Germplasm (IA Zone 3)

Cultivated variety (cultivar): Midas (KS)

References

Chayka, K. (n.d.). Heliopsis helianthoides (smooth oxeye). Minnesota Wildflowers. https://minnesotawildflowers.info/flower/smooth-oxeye

Cochrane, T. S., Elliot, K., & Lipke, C. S. (2014). Ox-eye. In Prairie plants of the University of Wisconsin-Madison Arboretum (3rd ed., p. 88). University of Wisconsin-Madison Arboretum.

Hilty, J. (2019). False sunflower - Heliopsis helianthoides. Illinois Wildflowers. https://www.illinoiswildflowers.info/prairie/plantx/fs_sunflowerx.htm  

Houseal, G. A. (2007). Forbs wildflowers. In G. A. Houseal (Eds.), Tallgrass Prairie Center’s native seed production manual (pp. 36–37). Tallgrass Prairie Center - University of Northern Iowa.

Kartesz, J.T., The Biota of North America Program (BONAP). 2023. North American Plant Atlas. (http://bonap.net/napa). Chapel Hill, N.C. [maps generated from Kartesz, J.T. 2023. Floristic Synthesis of North America, Version 1.0. Biota of North America Program (BONAP). (in press)]

NatureServe. 2024. NatureServe Network Biodiversity Location Data accessed through NatureServe Explorer [web application]. NatureServe, Arlington, Virginia. Available https://explorer.natureserve.org/. (Accessed: February 29, 2024).

Runkel, S. T., & Roosa, D. M. (2009). Ox-eye. In Wildflowers of the tallgrass prairie: The upper Midwest (2nd ed., pp. 162–163). University of Iowa Press.

Smith, A. R. (2020, November 6). Heliopsis helianthoides (Linnaeus) Sweet. Flora of North America. http://floranorthamerica.org/Heliopsis_helianthoides 

USDA NRCS National Plant Data Team. (n.d.). Heliopsis helianthoides (L.) Sweet. USDA plants database. https://plants.usda.gov/home/plantProfile?symbol=HEHE5 

Species Guide Updated 12/11/2024

Eutrochium maculatum (L.) E. E. Lamont

Alternate Common Names: purple boneset, spotted trumpetweed

Scientific Synonyms: Eupatoriadelphus maculatus (L.) R. M. King & H. Rob., Eupatorium maculatum L., Eupatorium purpureum  L. var. maculatum  (L.) Darl., Eupatorium purpureum subsp. maculatum (L.) Á. Löve & D. Löve, Eupatorium trifoliatum var. maculatum (L.) Farwell

Family: ‌aster or sunflower family (Asteraceae)

Functional Group: forbs (wildflowers)

Description 

Life cycle and growth form

Perennial, spreads slowly by rhizomes to form clumps.

Height: 2-10 ft (mostly 3-6 ft) 

 

Leaves and stem

Lance-shaped, up to 9 in long with serrated margins, whorled in groups of 4-5 (usually) at each node; unbranched stems purple to purple-spotted (the name ‘maculatum’ means spotted and refers to this trait).

 

Flower, fruit and seedhead

Flower: 3-5 small, indistinct florets per head, in flat-topped to domed inflorescences with dozens to hundreds of pink to purplish heads (rarely white); inflorescences appear fuzzy due to the long styles that stick out of the florets.

Fruit/seedhead: Seed clusters ripen from the center outward, becoming tan and fluffy as seed matures; seed is wind-dispersed and susceptible to shattering in windy weather.

Pollination: Insects, particularly bees and butterflies.

 

Seed

Appendix D

‌Seed characteristics 

Seeds per ounce: 95,000 (IA NRCS)

1000 seed weight: 0.28 g (Seed Information Database)

Description: Slender, charcoal-gray seeds about 3 mm long with a tuft of tan pappus.

Typical seed test 

PLS: 74% (n = 5)

Purity: 86% (n = 5)

Germination: 17% (n = 4)  

Dormant: 72% (n = 4)

(averages obtained from n tests of purchased seed lots)

Habitat and range

‌Habitat: Moist to wet soil; full sun; wet prairies, sedge meadows, fens, ditches, and other wet places. The USDA classifies it as an Obligate Wetland species in the Midwest region. It benefits from irrigation in production systems.

Conservation status: Global- G5, secure; Idaho and West Virginia- S1, critically imperiled; Montana- S1/S2, critically imperiled to imperiled; Arizona, Virginia, and Georgia- S2, imperiled; Wyoming- S3, vulnerable (NatureServe) 

General Comments

The sweet-scented flowerheads attract numerous and diverse pollinators including the endangered rusty patched bumble bee. We once identified seven species of butterflies along a 150 foot row of flowering spotted joe pye weed in one 15-minute observation. Traditional uses of this species by Native tribes include treatments for digestive, urinary, kidney, and women’s complaints and using the hollow stems as straws. The clumped stems and whorled leaves produce dense shade that excludes most weeds from a well-established plot. Irrigation is important for seed production.

Recommendations for Seed Production 

Establishment for seed production

‌Direct seeding

We do not have experience direct seeding this species for seed production.

‌‌Greenhouse

Seed pre-treatment: 60 days cold-moist stratification.

Sowing: Seed is small and should be surface sown or very lightly covered or seedlings will not have enough energy to emerge. If started in germination flats, transplant to individual plugs when seedlings have their first pair of true leaves.

Transplanting: Seedlings are ready to transplant to the field about 8-12 weeks after starting in plugs, when their roots are well-branched and numerous root tips are visible at hole(s) in the base of the plug. Pop out a few plugs to check for adequate root development that will provide sturdy plugs for planting. A week or two before transplanting, move flats outside to ‘harden off.’ (See Propagation chapter in General Information for more details).

‌Appendix A

Stand management

Weeds: In the first season after transplanting, weeds are suppressed by a plastic weed barrier. Plants spread by short rhizomes; in second and subsequent years, holes in plastic must be expanded or plastic removed to make room for new stems. Well-established plots shade out most weeds.

Pests: None noted.

Diseases: None noted.

Soil moisture: Irrigation is necessary in most soils to obtain maximum seed yield.

Seed production

First harvest: Plants flower and set a little seed the first year when transplanted in spring.

Yield: 29-226 pounds/acre (based on 1 plot)

Stand life: Peak seed production in years 3-5, but plants are long-lived and vigorous for many years.

Flowering date: late July - early September in northeast Iowa

Seed maturity/Harvest date: second to third week of September

Seed retention: Seeds are wind dispersed soon after maturity, when fluff (pappus) expands in late August through September.

Harvest date range at TPC (2016-2022): Aug 26 - Oct 3

Recommended harvest method: Watch for the centers of seed clusters to begin shattering, and pick early maturing seed heads (clip stalks below seed clusters). If some heads in a cluster are still closed (not fluffy), pull apart a few heads to see if the seeds are dark colored and separate easily from the base (receptacle). Combine the rest of the plot at peak maturity. Turn off air or combine will disperse the fluffy seeds.

Appendix B

Seed cleaning and storage

Cleaning process: If hand clipped, run dried material through a 1/4 in mesh to thresh seed from stalks. Use a brush machine (medium bristles, minimum vacuum) to remove pappus. Winnow with a box fan to separate seed from most of the pappus and chaff. Airscreen 2-3 times to finish cleaning. See Appendix C for specific settings.

Seed storage: cool/dry (33-50° F, 30-50% RH)

Appendix C

Released Germplasm 

Source Identified material: Natural Selections/Iowa Ecotype Zone 1

Cultivated variety (cultivar): ‘Gateway’ is a compact cultivar used in landscaping.

References

Chayka, K. (n.d.). Eutrochium maculatum (spotted joe-pye weed). Minnesota Wildflowers. https://www.minnesotawildflowers.info/flower/spotted-joe-pye-weed

Eutrochium maculatum. (2024). Prairie Moon Nursery. https://www.prairiemoon.com/eutrochium-maculatum-joe-pye-weed-prairie-moon-nursery.html

Hilty, J. (n.d.). Spotted joe-pye weed - Eutrochium maculatum. Illinois Wildflowers. https://www.illinoiswildflowers.info/wetland/plants/sp_joepye.htm 

Kartesz, J.T., The Biota of North America Program (BONAP). 2023. North American Plant Atlas. (http://bonap.net/napa). Chapel Hill, N.C. [maps generated from Kartesz, J.T. 2023. Floristic Synthesis of North America, Version 1.0. Biota of North America Program (BONAP). (in press)]

Lamont, Eric E. (2020, November 6). Eutrochium maculatum (Linnaeus) E. E. Lamont. Flora of North America. http://floranorthamerica.org/Eutrochium_maculatum 

Missouri Botanical Garden. (n.d.). Eutrochium maculatum “Gateway.” Plant Finder. https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=302488&is

Moerman, D. (2003). Native American ethnobotany database. BRIT. http://naeb.brit.org/

NatureServe. 2024. NatureServe Network Biodiversity Location Data accessed through NatureServe Explorer [web application]. NatureServe, Arlington, Virginia. Available https://explorer.natureserve.org/. (Accessed: February 28, 2024).

North Carolina State Extension (n.d.) Eutrochium maculatum. North Carolina Extension Gardener Plant Toolbox. https://plants.ces.ncsu.edu/plants/eutrochium-maculatum/

SER, INSR, RBGK, Seed Information Database (SID). (2023). Eupatorium maculatum. https://ser-sid.org/species/567dc915-c79f-4608-a9d6-e1351ee9a2cb 

USDA NRCS National Plant Data Team. (n.d.). Eutrochium maculatum (L.) E.E. Lamont. USDA plants database. https://plants.usda.gov/plant-profile/EUMA9

Species Guide Updated 12/19/2024

Asclepias incarnata L. 

Alternate Common Names: rose milkweed, silkweed, water nerve root, white Indian hemp, swamp silkweed

Family: ‌dogbane family (Apocynaceae), formerly assigned to the milkweed family (Asclepiadaceae)

Functional Group: forbs (wildflowers)

Description 

Life cycle and growth form

Perennial, weakly rhizomatous, forming small clones of several stems; root systems are more fibrous than other commonly cultivated milkweeds such as butterfly milkweed (e.g., A. tuberosa).

Height: 2-5 ft

‌

Leaves and stem

Leaves 3-6 in long, usually narrowly lanceolate with smooth, untoothed edges and sessile on the stem or short-stalked, opposite arrangement; stems mostly hairless, usually unbranched (occasionally branched above).

 

Flower, fruit and seedhead

Flower: Numerous, various shades of rose-pink with a pronounced fragrance similar to bubblegum, in domed clusters 2-3 in across; individual flowers five-parted, radially symmetrical, with a crown of five tubular hoods surrounding a central column, petals and sepals curved downward (typical milkweed flowers).

Fruit/seedhead: Pods (follicles) are 2-4 in long, smooth/waxy, and teardrop-shaped; follicles open along one side at maturity, revealing many shiny brown seeds each of which bears a flattened wing and a plume of soft, white floss.

Pollination: Pollination: Insects, particularly butterflies and bees.

Seed

Appendix D

‌Seed characteristics 

Seeds per ounce: 4,800 (IA NRCS)

1000 seed weight: 3.65 g (Seed Information Database)

Description: Dark brown, oval, surrounded by flattened ‘wing’ and tuft of soft hairs.

Typical seed test 

PLS: 89% (n = 11) 

Purity: 98% (n = 11)

Germination: 7% (n = 7)

Dormant: 58% (n = 7)

(averages obtained from n tests of purchased seed lots)

Habitat and range

‌Habitat: Moist to wet, neutral to slightly acidic soil; partial to full sun open floodplains, lakeshores, ditches, wet prairies. Wetland Indicator Status is Obligate Wetland (OBL) for the Midwest. Benefits from irrigation in production systems.

Conservation status: Global- G5, secure; Arizona, Mississippi, Montana, and Nevada- S1, critically imperiled; Arkansas, Idaho, and Louisiana- S2, imperiled; Wyoming- S2/S3 imperiled to vulnerable; Georgia- S3, vulnerable (NatureServe)

‌

General Comments

Swamp milkweed is a valuable addition to pollinator habitat plantings on wetter soils and a showy, mannerly milkweed for home landscaping. This species is an important host for caterpillars of the monarch butterfly which feed upon its leaves. The fragrant flowers attract and provide nectar for numerous pollinators including various species of butterflies, bees, wasps, and flies. The strong, silky stem fibers are used as nesting material by songbirds and have traditionally been used for spinning and weaving by Native peoples, giving rise to some of the alternate common names such as silkweed and white Indian hemp. Establishment from plugs is rapid, and seed can be harvested the first fall, but production stands are short-lived (2-3 years).

Recommendations for Seed Production 

Establishment for seed production

‌Direct seeding

We do not have experience with direct seeding this species for seed production. 

‌‌Greenhouse

Seed pre-treatment: To break dormancy, use 30-60 days cold stratification (check frequently for early germination) or a 24-hour soak in 250 ppm gibberellic acid (GA-3).

Sowing: Seed directly into plugs (2-3 seeds per cell) or on germination flat and lightly cover with potting mix, or germinate between sheets of moistened paper toweling and move to individual plugs as radicles (seed roots) emerge from seeds; start seeds 8-10 weeks before the average frost-free date.

Transplanting: Move plug flats outdoors 1-2 weeks before transplanting to allow seedlings to adjust to ambient conditions; plant with 1 ft spacing in plastic mulch with drip irrigation.

‌Appendix A

Stand management

Weeds: Field preparation through repeated tillage and application of plastic mulch reduces weed issues; hand harvesting of pods as they mature results in very pure seed.

Pests: Non-native oleander aphids (Aphis nerii) can form dense infestations, reducing plant vigor and causing abortion of flowers or pods or, in extreme cases, death of the plant. Scout for these golden yellow aphids when plants are in bud, as it is easier to control small aphid infestations. Aphid predators (e.g., ladybug larvae, hoverfly larvae, and lacewing larvae) and aphid mummy wasps help reduce damage.  Use the least toxic treatment possible (e.g., horticultural oils or insecticidal soaps) to avoid harming aphid enemies and pollinators, as aphids often occur at the time plants are in flower. Native seed-feeding milkweed bug species (Oncopeltus fasciatus and Lygaeus kalmii) pierce pods and feed on seeds. Manually remove clusters of red-orange milkweed bug nymphs from pods. A small proportion of pods is ruined by larvae of native milkweed stem weevils (Rhyssomatus lineaticollis or R. annectans). These appear as grubs or pupae inside the cluster of seeds. Affected pods have a small entry hole on the side and often mature prematurely. Earlier in the growing season, red milkweed longhorn beetles (Tetraopes spp.) feed on the tips of milkweed leaves. Their larvae feed within milkweed roots and rhizomes and may weaken plants over time. Monarch butterflies (Danaus plexippus) are attracted to lay eggs on swamp milkweed. In smaller-scale production systems, caterpillars can be hand-picked from production rows and transferred to nearby wild milkweeds before applying treatments for problem insects.

Diseases: Milkweeds are susceptible to a variety of fungal, bacterial, and viral diseases. Cultural methods such as reducing stand size or density, intercropping, and crop rotations may reduce disease spread and severity.

 Hybridization risk: This species is known to hybridize with related species Asclepias hirtella, A. purpurascens, A. sullivantii, A, syriaca, A. tuberose, A. verticillata.

Soil moisture: Plant in naturally wet soils and/or supply irrigation, especially in dry weather.

Note: Refer to Milkweeds: A Conservation Practitioner’s Guide, published by the Xerces Society, for more detailed information on milkweed insects and diseases and their control.

Seed production

First harvest: Fall of planting year, when started from transplanted plugs.

Yield: 200-300 pounds/acre, with largest harvest in the first year (based on 4 plots)

Stand life: Two years from transplanting. Plants are reported to be longer lived in natural populations.

 

Flowering date: July in northern Iowa

Seed maturity/Harvest date:  Early September - mid-October in northern Iowa

Seed retention: Seed is released as individual pods ripen and split open in early September through the beginning of October.

Harvest date range at TPC (2009-2020): Aug 31 - Oct 17

Recommended harvest method: Harvest by hand as pods (follicles) mature; collect pods that are changing color from green to yellowish and split when subjected to gentle pressure on the suture (seam), revealing dark brown seeds.

Appendix B

Seed cleaning and storage

Cleaning process: Dry pods in cloth bags for two weeks with fan-forced air. Pass pods through a debearder or stationary combine to release seeds and detach fluff. Follow up by fan winnowing (outside on a relatively calm day) to remove most of the fluff. Air-screen the remaining material. Indent cylinder removes broken bits of pods and stems from seed.

Seed storage: cool/dry (33-50° F, 30-50% RH)

Appendix C

Released Germplasm 

Source identified material: Natural Selections/Iowa Ecotype Zones 1, 2, IA

Cultivated variety (cultivar): ‘Ice Ballet,’ ‘Cinderella,’ and ‘Milkmaid’

References

Borders, B. and E. Lee-Mäder. 2014. Milkweeds: A Conservation Practitioner’s Guide. 143 pp. Portland, OR. The Xerces Society for Invertebrate Conservation. https://www.xerces.org/sites/default/files/2018-05/17-031_02_XercesSoc_Milkweeds-Conservation-Guide_web.pdf

Chayka, K. (2010). Asclepias incarnata (swamp milkweed). Minnesota Wildflowers. https://www.minnesotawildflowers.info/flower/swamp-milkweed  

Cochrane, T. S., Elliot, K., & Lipke, C. S. (2014). Swamp milkweed. In Prairie plants of the University of Wisconsin, Madison Arboretum (3rd ed., p. 55). University of Wisconsin-Madison Arboretum. 

Hilty, J. (2020). Swamp milkweed - Asclepias incarnata. Illinois Wildflowers. https://www.illinoiswildflowers.info/wetland/plants/sw_milkweed.htm  

Kartesz, J.T., The Biota of North America Program (BONAP). 2023. North American Plant Atlas. (http://bonap.net/napa). Chapel Hill, N.C. [maps generated from Kartesz, J.T. 2023. Floristic Synthesis of North America, Version 1.0. Biota of North America Program (BONAP). (in press)]

Kirk, S. and Belt, S. (2011). Plant fact sheet for swamp milkweed (Asclepias incarnata). USDA-Natural Resources Conservation Service, Norman A. Berg National Plant Materials Center. Beltsville, MD 20705. https://plants.usda.gov/DocumentLibrary/factsheet/pdf/fs_asin.pdf

  Native Plant Trust (2024). Asclepias incarnata. https://plantfinder.nativeplanttrust.org/plant/Asclepias-incarnata

NatureServe. 2024. NatureServe Network Biodiversity Location Data accessed through NatureServe Explorer [web application]. NatureServe, Arlington, Virginia. Available https://explorer.natureserve.org/. (Accessed: February 28, 2024).

Runkel, S. T., & Roosa, D. M. (2009). Swamp milkweed. In Wildflowers of the tallgrass prairie: The upper Midwest (Second, p. 179). University of Iowa Press. 

Schultz, Jan; Beyer, Patty; Williams, Julie. (2001). Propagation protocol for production of Container (plug) Asclepias incarnata L. plants USDA FS - Hiawatha National Forest Marquette, Michigan. In: Native Plant Network. US Department of Agriculture, Forest Service, National Center for Reforestation, Nurseries, and Genetic Resources. https://NativePlantNetwork.org (accessed 2024/01/09).

Society for Ecological Restoration and Royal Botanic Gardens Kew. (2024). Asclepias incarnata L. SWAMP MILKWEED. Seed Information Database. https://ser-sid.org/species/62fbef4e-ed33-4c71-a18f-f78f9018fda7 

University of Wisconsin. (2024). Common milkweed insects. Wisconsin Horticulture, Division of Extension. https://hort.extension.wisc.edu/articles/common-milkweed-insects/

Species Guide Updated 12/19/2024

Verbena hastata L.

Alternate Common Names: blue vervain, simpler’s joy, American blue vervain, American simpler’s joy, wild hyssop

Family: ‌verbena family (Verbenaceae)

Functional Group: forbs (wildflowers)

Description 

Life cycle and growth form

Perennial, short-rhizomatous.

Height: 2-6 ft 

 

Leaves and stem

‌

Leaves are opposite, lance-shaped (up to 6 in long and 1 in wide), coarsely toothed, strongly veined above, and usually short-hairy beneath; stems square, grooved, and green to purple, with flattened hairs, often branched in the upper half of the plant.

Flower, fruit and seedhead

Flower: Individual flowers are blue-purple, 1/4 in across, with five expanded lobes (petals) attached to a short tube; flowers are arranged in a branched “candelabra” (panicle) of spikes; spikes elongate through the flowering season as new flowers emerge in whorls (rings) near the tops while seeds (nutlets) mature near their bases.

Fruit/seedhead: Each calyx of fused sepals contains four developing seeds (nutlets); spikes ripen from the bottom up.

Pollination: Insects, particularly bees.

Seed

Appendix D

‌Seed characteristics 

Seeds per ounce: 93,000 (IA NRCS)

1000 seed weight: 0.23 g (Seed Information Database)

Description: Seed unit is technically a type of dry fruit called a nutlet. Rust-brown nutlets are 2 mm long and approximately 0.5 mm wide.

Typical seed test 

PLS: 97%

Purity: 100%

Germination: 13%

Dormant: 84%

(averages obtained from 5 tests of purchased seed lots)

Habitat and range

‌Habitat: Swamp verbena grows best in full sun and moist to wet, organic-rich soils. Plants are typically found in wet places such as wet prairies, sedge meadows, fens, and ditches. Wetland Indicator Status is Facultative Wetland (FACW) for the Midwest. Production fields benefit from irrigation.

Conservation status: Global- G5, secure; North Carolina- S2/S3, imperiled to vulnerable; Wyoming- S3, vulnerable (NatureServe)

General Comments

Swamp verbena is well suited for planting in moist soils or seasonally wet sites such as roadside ditches. It grows quickly and flowers in the planting year, producing abundant seed that is relatively easy to harvest and clean. Most mammalian herbivores avoid the bitter foliage, hence this species has persisted even in heavily grazed, wet prairie pastures. Swamp verbena has a long flowering period and is visited by diverse species of bees and small butterflies. The seeds are eaten by native sparrows and juncos. Swamp verbena has numerous uses in traditional Native medicine, including as a treatment for digestive and obstetric complaints. Caution: Extracts of this species are known to interfere with prescription medication and can cause vomiting and diarrhea in high doses.

Recommendations for Seed Production 

Establishment for seed production

‌Direct seeding

We do not have experience direct seeding this species for seed production.

‌‌Greenhouse

Seed pre-treatment: Cold/moist stratification is recommended. Different sources suggest a minimum of 30 days (RNGR) up to 3 months (NRCS Plant Guide). Most northern Iowa accessions showed high rates of germination after 30 day stratification, but a few accessions appeared to have a higher degree of dormancy. In these cases, we saw a second flush of germination after a week of very high temperatures in the greenhouse, more than 2 months after sowing. 

Sowing: Sow seed on surface of germination mix (light needed for germination).

Transplanting: Seedlings grow rapidly with fibrous root systems that form firm plugs for transplanting. Plan on sowing seed in greenhouse containers 8-10 weeks before transplanting. If seedlings grow too tall in plug trays, they should be pinched back to adjust the shoot:root ratio.

‌Appendix A

Stand management

Weeds: Plastic mulch prevents weed competition in the first year, and tall fast-growing verbena plants are fairly competitive. Holes in the plastic may need to be widened to accommodate rhizomatous spread in the second and subsequent years. Focus weeding or roguing efforts on weeds that could contaminate the seed (i.e., species with small, elongated seed).

Pests: None noted. Bitter foliage deters mammalian herbivores.

Diseases: None noted, though plants appear to be short-lived (2-4 years) in production rows.

Hybridization risk: Maintain separation between fields of swamp verbena and other species in the genus Verbena (e.g., hoary vervain, Verbena stricta) as hybrids readily form. 

Soil moisture: Irrigation is recommended.

Seed production

First harvest: In planting year, when grown from transplants.

Yield: 440-610 pounds/acre (based on 2 plots)

Stand life: Estimated 3-4 years, with peak harvest in year one.

Flowering date: late June - September

 

Seed maturity/Harvest date: mid-September - mid-October

Seed retention: Shattering begins as seedheads turn from purple to brown in mid-September through mid-October.

Harvest date range at TPC (2021-2023): Sept 16 - Oct 19

Recommended harvest method: Seed heads turn from green to purple to brown as they mature. Harvest when all, or nearly all, parts of the spikes have turned brown. Some seeds will shatter from lower parts of spikes as the seeds in the upper parts mature, but most seed is retained on the plant. Hand harvest early maturing individuals to preserve genetic diversity, then combine the rest of the plot at peak maturity.

Appendix B

Seed cleaning and storage

Cleaning process

Hand-collected material: Dry on tarp or in a cloth bag for 2 weeks. Thresh by passing through a stationary combine or by stomping/beating material on the tarp or in a plastic tub. Pass through a ¼ in and ⅛ in mesh to remove sticks before airscreening.

Combined material: Hand-collected material: Dry on tarp or in a cloth bag for 2 weeks. Thresh by passing through a stationary combine or by stomping/beating material on the tarp or in a plastic tub. Pass through a 1/4 in and 1/8 in mesh to remove sticks before airscreening. 

Note: Airscreening one-two times results in a very pure product.

Seed storage 

cool/dry (33-50° F, 30-50% RH)

Appendix C

Released Germplasm 

Source Identified material: Natural Selections/Iowa Ecotype Zone NI

References

Chayka, K. (n.d.). Verbena hastata (blue vervain). Minnesota Wildflowers. https://www.minnesotawildflowers.info/flower/blue-vervain 

Hilty, J. (2019). Blue vervain - Verbena hastata. Illinois Wildflowers. https://www.illinoiswildflowers.info/wetland/plants/bl_vervain.htm 

Kartesz, J.T., The Biota of North America Program (BONAP). 2023. North American Plant Atlas. (http://bonap.net/napa). Chapel Hill, N.C. [maps generated from Kartesz, J.T. 2023. Floristic Synthesis of North America, Version 1.0. Biota of North America Program (BONAP). (in press)]

Kirk, S. and S.Belt. (2010).  Plant fact sheet for blue vervain (Verbena hastata).  USDA-Natural Resources Conservation Service, Norman A. Berg National Plant Materials Center.  Beltsville, MD 20705.

Moerman, D. (2003). Native American ethnobotany database. BRIT. http://naeb.brit.org/

NatureServe. 2024. NatureServe Network Biodiversity Location Data accessed through NatureServe Explorer [web application]. NatureServe, Arlington, Virginia. Available https://explorer.natureserve.org/. (Accessed: February 28, 2024).

North Carolina State Extension (n.d.) Verbena hastata. North Carolina Extension Gardener Plant Toolbox. https://plants.ces.ncsu.edu/plants/verbena-hastata/

Society for Ecological Restoration, International Network for Seed Based Restoration and Royal Botanic Gardens Kew. (2023) Seed Information Database (SID). Available from: https://ser-sid.org/ (February 2023)

USDA-NRCS. (2022). Conservation cover native seeding calculator [Excel File]. Retrieved from https://bit.ly/IA_OTH_Conservation_Cover-Native_Seeding_Calculator_2022

USDA NRCS National Plant Data Team. (n.d.). Verbena hastata L. USDA plants database. https://plants.usda.gov/plant-profile/VEHA2 

Species Guide Updated 12/18/2024

Artemisia ludoviciana Nutt.

Alternate Common Names: white sage, prairie sage, western mugwort, Louisiana sage, prairie wormwood, cudweed, mugwort, dark-leaved mugwort, sagewort, western sage, sailor’s tobacco, sagebrush

Scientific Synonym: Artemisia vulgaris var. ludoviciana (Nuttall) Kuntze 

Functional Group: forbs (wildflowers)

Family: ‌aster or sunflower family (Asteraceae)

Description 

Life cycle and growth form

Perennial, spreading by rhizomes to form large colonies that exclude some other plants.

Height: 1-3 ft

‌

Leaves and stem

‌

Alternate leaves, aromatic when crushed, of variable shape but mostly narrow, elongated ellipses up to 1 in wide and 3.5 (occasionally up to 5) in long, short-stalked or sessile, with silvery-white hairs on leaves and stems giving them a felt-like texture; stems may be branched or unbranched.

Flower, fruit and seedhead

‌Flower: Individual florets are inconspicuous within silvery, barrel-shaped, 1/8 in heads arranged in clusters in upper leaf axils or in spike-like to open, branched arrays up to 17 in in length; at full flowering, yellow stamens and minute, yellow to reddish corollas may be visible; wind-pollinated.

Fruit/seedhead: Roughly cylindrical in shape, approximately 1/8 in long, pappus is absent, heads open to release seed (achenes) when mature.

‌

Seed

Appendix D

‌Seed characteristics 

Seeds per ounce: 250,000 (IA NRCS)

1000 seed weight: 0.11 g (Seed Information Database)

Description: Cypsela (achene), elliptical in outline, about 0.5 mm long, light grayish-brown, without hairs or attached fluff (pappus).

Typical seed test 

PLS: 84% (n = 11)

Purity: 92% (n = 11)

Germination: 30% (n = 10)

Dormant: 57% (n = 11)

(averages obtained from n tests of purchased seed lots)

Habitat and range

Habitat: Dry to mesic soil; full sun; sandy or rocky prairies, roadsides. Wetland Indicator Status is Obligate Upland (UPL) for the Midwest.

Conservation status: Global- G5, secure; Michigan- S1, critically imperiled (NatureServe)

‌

General Comments

All above ground parts of the plant have a distinctive sage-like fragrance when rubbed or crushed. This species has traditional medicinal and ceremonial uses among numerous Native American tribes. Because it is wind-pollinated, white sagebrush is not considered a resource for pollinators, though it is a larval host for at least one species of moth caterpillar, Phaneta argenticostana. Its mode of vegetative spread produces a dense network of rhizomes and roots that function in erosion control.

Recommendations for Seed Production 

Establishment for seed production

‌Direct seeding

We do not have experience direct-seeding this species for seed production.

‌‌Greenhouse

Seed pre-treatment: 60 days cold-moist stratification (fine silica sand)

Sowing: Surface (seed is small and must not be buried too deeply); seed directly onto plug flats or start seedlings in germination trays and dibble into plugs when seedlings have first true leaves; start in greenhouse about 8-10 weeks prior to transplanting.

Transplanting: Harden off seedlings 1-2 weeks prior to transplanting; transplant with 12 in plant spacing in plasticulture plots or into bare soil in 36 in rows, after danger of frost; cut or remove plastic after the first full growing season to allow plants to spread by rhizomes.

Note: Also readily propagated through division or rhizome cuttings (see NRCS Plant Guide referenced below).

‌Appendix A

Stand management

Weeds: Few issues as dense, young colonies tend to exclude weeds; other small-seeded members of the aster family (e.g., frost aster, Symphyotrichum pilosum, and marestail, Erigeron canadensis) could contaminate seed and should be rogued out before harvest.

Pests: None noted.

Diseases: None noted.

Seed production

First harvest: In fall of first year when started from greenhouse transplants.

Yield: 15-60 pounds/acre (based on 5 plots)

Stand life: Peak seed production in the first two years, then declining.

Flowering date: late August - September

Seed maturity/Harvest date: Mid-October in northeast Iowa; gauge maturity by sampling heads from several plants and crushing to reveal developing seeds (a hand lens is helpful); mature seed will have a grayish-brown color and separate easily from the receptacle; watch for heads to open and release seed when mature; seed shatters easily and will be lost if harvest delayed.

Seed retention: Shattering begins once seedheads open in mid to late October.

Harvest date range at TPC (2003-2023): July 17 - Oct 28

Recommended harvest method: Combine at maturity or cut/swath stems when about 10% of plants in the plot have open seed heads and lay to dry in shed, then run through stationary combine.

Appendix B

Seed cleaning and storage

Cleaning process: Brush (Westrup LA-H) with stiff bristles and #14 screen mantle to release seed from heads, use minimal vacuum; airscreen several times.

Seed storage: cool/dry (33-50° F, 30-50% RH)

Appendix C

Released Germplasm 

Source identified material: Natural Selections/Iowa Ecotype Project Zones 1, 2, and 3

Cultivated variety (cultivar): Summit (LA); horticultural varieties may also exist.

References 

Chayka, K. (n.d.). Artemisia ludoviciana (white sage). Minnesota Wildflowers. https://www.minnesotawildflowers.info/flower/white-sage

Christiansen, P., & Muller, M. (1999). White sage - Artemisia ludoviciana Nutt. Prairie plants of Iowa - Artemisia ludoviciana Nutt. https://uipress.lib.uiowa.edu/ppi/display.php?record=Artemisia_ludoviciana

Cochrane, T. S., Elliot, K., & Lipke, C. S. (2014). White sage. In Prairie plants of the University of Wisconsin, Madison Arboretum (3rd ed., p. 68). University of Wisconsin-Madison Arboretum. 

Flora of North America Editorial Committee. 2006a. Flora of North America North of Mexico. Vol. 19. Magnoliophyta: Asteridae, part 6: Asteraceae, part 1. Oxford University Press, New York. xxiv + 579 pp.

Hilty, J. (2020). White sage - Artemisia ludoviciana. Illinois Wildflowers.   https://www.illinoiswildflowers.info/prairie/plantx/white_sagex.htm

Kartesz, J.T., The Biota of North America Program (BONAP). 2023. North American Plant Atlas. (http://bonap.net/napa). Chapel Hill, N.C. [maps generated from Kartesz, J.T. 2023. Floristic Synthesis of North America, Version 1.0. Biota of North America Program (BONAP). (in press)]

NatureServe. 2024. NatureServe Network Biodiversity Location Data accessed through NatureServe Explorer [web application]. NatureServe, Arlington, Virginia. Available https://explorer.natureserve.org/. (Accessed: February 16, 2024).

Runkel, S. T., & Roosa, D. M. (2009). Prairie sage. In Wildflowers of the tallgrass prairie: The upper Midwest (Second, p. 237). University of Iowa Press. 

Shultz, Leila M. (2020, November 6). Artemisia ludoviciana Nuttall. Flora of North America. http://floranorthamerica.org/Artemisia_ludoviciana  

Society for Ecological Restoration, International Network for Seed Based Restoration and Royal Botanic Gardens Kew. (2023) Seed Information Database (SID). Available from: https://ser-sid.org/ (February 2023)

Stevens, M., & Roberts, W. (2000). Plant guide - USDA Plants Database - White sage, Artemisia ludoviciana Nutt. https://plants.usda.gov/DocumentLibrary/plantguide/pdf/cs_arlu.pdf 

Species Guide Updated 12/19/2024